Re: Fix bug in multixact Oldest*MXactId initialization and access

Sami Imseih <samimseih@gmail.com>

From: Sami Imseih <samimseih@gmail.com>
To: Yura Sokolov <y.sokolov@postgrespro.ru>
Cc: "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, Heikki Linnakangas <hlinnaka@iki.fi>, Andres Freund <andres@anarazel.de>, Chao Li <li.evan.chao@gmail.com>
Date: 2026-02-26T16:34:17Z
Lists: pgsql-hackers
> But I still use inline procs for access to the arrays. Asserts cost nothing
> in release build. And new version of functions doesn't branch.

Asserts may have minimal impact for most builds, but my concern is
this is all unnecessary complexity. I mean if we guarantee that the
arrays are initialized correctly, maybe we can have an assert at
init time, why would we need asserts at run time?

--
Sami Imseih
Amazon Web Services (AWS)



Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add test for row-locking and multixids with prepared transactions

  2. Skip prepared_xacts test if max_prepared_transactions < 2

  3. Fix OldestMemberMXactId and OldestVisibleMXactId array usage

  4. Redefine backend ID to be an index into the proc array

  5. Fix an old bug in multixact and two-phase commit. Prepared transactions can